Clarithromycin: Uses, Dosage, Side Effects & Precautions

Clarithromycin is a macrolide antibiotic used to treat respiratory tract infections, skin infections, and Helicobacter pylori infections. It works by inhibiting bacterial protein synthesis, which kills bacteria or stops their growth. This guide covers clarithromycin uses, how it works, dosage, side effects, precautions, drug interactions, use in pregnancy and breastfeeding and its approximate price in India.

Clarithromycin at a Glance

Common Indications of Clarithromycin

• Respiratory infections (bacterial flare-ups of chronic bronchitis, pneumonia)
• Uncomplicated skin infections
• Helicobacter pylori (with other medications)
• Sinus infections
• Throat and tonsil infections, as an alternative when first-choice antibiotics cannot be used
• Middle ear infections in children

Clarithromycin works only against susceptible bacteria. It does not treat viral infections such as colds or flu.

Clarithromycin Dosage and Administration

Adults: The dose depends on the infection being treated. Common dosing for many bacterial infections is 250–500 mg orally every 12 hours, with treatment duration depending on the infection. Different infections can require different doses and durations.

1. pylori treatment: Clarithromycin may be used as part of combination treatment for H. pylori when appropriate. This is a prescribed regimen with other medicines and should never be self-dosed. The choice of regimen depends on previous antibiotic exposure and clarithromycin susceptibility/resistance. Clarithromycin-containing regimens should generally be avoided unless clarithromycin susceptibility has been demonstrated.

Children: Dosing is weight-based and depends on the infection being treated. For many bacterial infections, the usual pediatric dose is approximately 15 mg/kg/day divided into two doses for 10 days, with the exact dose and duration determined by a healthcare professional. Different dosing may apply for certain infections. Kidney function can also affect dosing. Safety and effectiveness in babies under 6 months of age have not been established.

Clarithromycin is available in oral tablets and suspension forms. Immediate-release tablets can be taken with or without food, while extended-release tablets should be taken with food.

Take this medicine only as advised by your doctor or healthcare professional. Do not start, stop, or change the dose on your own.

Using Antibiotics Responsibly

• Clarithromycin treats bacterial infections, not viral colds or flu.
• Use it only when prescribed for an appropriate bacterial infection.
• Take it exactly as prescribed, and follow the treatment duration your healthcare professional has given you.
• Do not skip doses, stop early, extend treatment, or save leftover antibiotics for later unless a healthcare professional tells you to. If you feel better or worse, or have side effects, speak to your doctor about what to do.
• Unnecessary or incorrect antibiotic use contributes to antimicrobial resistance, which makes infections harder to treat.

Adverse Effects of Clarithromycin

Common side effects:

• Diarrhea and nausea
• Vomiting
• Taste disturbances
• Abdominal pain
• Headache

Seek medical help promptly if you notice:

• Signs of a severe allergic reaction or serious skin reaction, such as a widespread, blistering or peeling rash
• Yellowing of the skin or eyes, dark urine, itching, loss of appetite or abdominal tenderness, which can be signs of liver problems
• A fast or irregular heartbeat, palpitations or fainting
• Severe or persistent diarrhea, which can occur during treatment or even weeks after treatment has ended and may be a sign of difficile infection

Contraindications of Clarithromycin

According to US prescribing information, clarithromycin should not be used in the following situations:

• Known hypersensitivity (allergy) to clarithromycin, erythromycin, or other macrolide antibiotics
• A history of cholestatic jaundice or liver dysfunction linked to earlier clarithromycin use
• Use together with any of these medicines: cisapride, pimozide, ergotamine, dihydroergotamine, lomitapide, lovastatin, simvastatin, or lurasidone
• Use together with colchicine in people with kidney or liver impairment

Other conditions and medicines call for caution or closer monitoring rather than being formal contraindications. These are described under Precautions and Drug Interactions.

Clarithromycin Precautions

• Heart rhythm (QT prolongation): Clarithromycin can prolong the QT interval and, infrequently, cause serious heart rhythm problems. It is generally avoided in people with known QT prolongation, serious ventricular arrhythmias, a clinically significant slow heart rate (bradycardia), or uncorrected low potassium or magnesium levels, and in those taking certain heart-rhythm medicines. Older adults may be more susceptible. Not everyone with a heart condition is affected in the same way, so tell your doctor about any heart problems.
• Coronary artery disease: A clinical trial reported an increased risk of death one year or more after clarithromycin treatment in people with coronary artery disease. The reason for this finding is uncertain, and other studies have reported mixed results. Doctors consider this information when weighing the potential benefits and risks of treatment.
• Myasthenia gravis: Clarithromycin may worsen symptoms in people with myasthenia gravis. Do not stop any prescribed medicine without medical advice, and let your doctor know promptly if muscle weakness worsens.

Pregnancy, Breastfeeding, Liver, and Kidney Considerations for Clarithromycin

• Pregnancy: Clarithromycin is generally not preferred when a suitable alternative is available. Current US prescribing information advises against its use during pregnancy unless no alternative treatment is appropriate. If you are pregnant or planning pregnancy, discuss antibiotic options with your doctor. If you become pregnant while taking it, speak to your doctor rather than stopping on your own.
• Breastfeeding: Clarithromycin passes into breast milk in small amounts. Significant effects in breastfed infants are considered unlikely, but tell your doctor if you are breastfeeding so they can consider the benefits of treatment and any potential effects on the infant. Let your doctor know if your baby develops diarrhea, a rash, or feeding problems.
• Liver: Caution in patients with liver disease. Tell your doctor promptly if you develop signs of liver problems. Some product information outside the US also advises against use in severe liver failure combined with kidney impairment.
• Kidneys: Dose adjustment may be required in renal impairment, with extra caution in severe renal impairment.

Clarithromycin Drug Interactions

Clarithromycin can raise the levels of many other medicines by blocking an enzyme (CYP3A) that helps clear them. Not every interaction means the medicines can never be used together. Some combinations must be avoided, while others may need a dose change or extra monitoring.

Must be avoided (contraindicated):

• Cisapride and pimozide
• Ergotamine and dihydroergotamine
• Lomitapide
• Lovastatin and simvastatin
• Lurasidone
• Colchicine in people with kidney or liver impairment

Generally avoided: certain heart-rhythm medicines, such as amiodarone, sotalol, quinidine, disopyramide, dofetilide and procainamide, because of the added risk to heart rhythm.

May require dose adjustment or monitoring:

• Colchicine (in people with normal kidney and liver function): the colchicine dose is usually reduced
• Warfarin: blood-clotting tests may need closer checking
• Digoxin
• Carbamazepine
• Other statins, such as atorvastatin and pravastatin
• Calcium channel blockers, such as verapamil, amlodipine, diltiazem and nifedipine
• Diabetes medicines, including insulin: risk of low blood sugar
• Sildenafil, tadalafil and vardenafil
• Theophylline
• Certain sedatives, such as midazolam, triazolam and alprazolam
• Quetiapine
• Cyclosporine and tacrolimus
• Some HIV medicines, such as atazanavir and ritonavir
• Rifampicin, which can lower clarithromycin levels
• St John’s Wort

Tell your doctor or pharmacist about all prescription and over-the-counter medicines, supplements and herbal products you use. This list is not complete.

Clarithromycin Brands, Strengths, and Price in India

Clarithromycin tablets are available in 250 mg and 500 mg strengths. Brand names available in India include Claribid and Clarimac.

Approximate Price in India

Claribid 500 mg, strip of 10 tablets: approximately ₹386 based on current online pharmacy pricing.

Prices can vary by brand, strength, pack size, pharmacy, location, and discounts. Check the current price of your prescribed brand at a licensed pharmacy.

How HealthPil Can Help

At HealthPil, you can consult a qualified healthcare professional if you have questions about clarithromycin, your symptoms, or whether an antibiotic is appropriate for your condition. Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about this medicine, its side effects, or your treatment plan, you can consult a doctor through HealthPil.